1. Technical Field
The present invention is directed to a device and a method for processing data for transfer through a data link; in particular, a method and a device for controlling the speed of data flow to a parallel to serial converter.
2. Discussion of Related Art
In data link and data transmission technology, a high bandwidth transmission medium, e.g., fiber optics, is used to transmit data serially at high speed. Prior to transmission of data through the high bandwidth medium, data is preprocessed by processing circuitry. For an N bit data, N latches are used to latch the N bits at a given clock rate to output onto an output bus. The N bit data on the output bus is then converted to serial data by a parallel to serial converter. Serial data is then output from the parallel to serial converter and transmitted through the high bandwidth medium. The data is received serially at the other end of the high bandwidth medium, and converted back to parallel data for processing. As an example, a Fibre Channel data link typically has processing circuitry for processing a 10-bit data. A 10-bit latch receives the 10-bit data and is clocked at the speed of 1,0625 MHz. The 10-bit data at the output is converted to serial data by a parallel to serial converter for transmission through a fibre data link. Generally, the data transmitted through the fibre or transmission medium is received serially at the end of the fibre link and the serial data is converted to parallel for processing at the receiving end.
With recent increased demand for high speed data links for operating in different environments, such as computer to computer networking or computer to peripheral networking, a need exists for a data processing device and method to transmit and receive data through the data link at selectably different speeds.